A general thermoelectric module has a structure in which a pair of PN joints are formed by joining a P-type thermoelectric element and an N-type thermoelectric element among metal electrodes. When a temperature difference exists between both metal electrodes of the pair of PN joints, power is generated by the Seeback effect, and accordingly the thermoelectric module may be a power generator. Also, according to Peltier's effect in which one of both of the metal electrodes of the pair of PN joints is cooled and the other metal electrode is heated, the thermoelectric module may be a temperature controller.
Such a thermoelectric module is applied to a cooler, a warmer, and a generator to provide various thermoelectric effects.
Accordingly, a method of increasing efficiency of a thermoelectric module has drawn attention.